1. Introduction
The present invention generally relates to a grounding wire clamping device utilized to secure or clamp a wire to a rigid substrate such as, for example, a wooden utility pole, building or the like. More specifically, the present invention relates to a device which aids the person handling the device (hereinafter "lineman") so as to facilitate easy placement and installation thereof.
2. The Prior Art
Various attempts have been made in the art to provide clamping means which secure a wire to a rigid substrate. Indeed, devices of the wire clamping genre are not new to the art, in and of themselves, as exemplified by the following prior-issued U.S. patents. For example, U.S. Pat. No. 3,341,651 to Odegaard generally discloses a clip for securing wire, cable or the like to a substrate. In accordance with Odegaard, a spike 40 having a bar 10 attached thereto is first driven into a substrate (e.g. concrete wall 52) and the bar 10 is subsequently bent into a U-shape so as to register the head 45 with opening 30a. Upon tapping of end 20 with a hammer or the like (as shown in Odegaard's FIG. 4) the tapered head 45 will be forced through opening 30a in the bottom of clamp 34 and into opening 30 thereby retaining bar 10 in its U-shape and thus securing cable 54 to wall 52. It is significant to note in Odegaard's FIG. 4 that it is necessary to manually retain bar 10 in its U-shaped position while simultaneously tapping end 20 so as to force spike head 45 through opening 30a.
In accordance with the present invention, however, once the wire is securely retained in the clamping device, the biasing nature thereof prevents axial slippage of the device relative to the wire so as to permit a lineman to have free use of his hands. This important advantage of the present invention is further underscored when consideration is given to the fact that a lineman normally wears thick rubber insulating gloves (typically about 1/8 inch thick) over which a protective outer leather glove is placed. Accordingly, a lineman's hands are typically encumbered by the use of such protective clothing and thus, the requirement of Odegaard's structure that the bar 10 be manually held in place becomes a readily apparent disadvantage to its use.
U.S. Pat. No. 3,906,592 to Sakasegawa et al provides a rather complicated interlocking tab/latch assembly 46, 45, respectively. However, once again, such an intricate and complicated interlocking tab/latch assembly in accordance with Sakasegawa et al not only increases the cost of manufacture but also does not lend itself to ready manipulation by a lineman who is wearing the relatively thick gloves briefly mentioned above.
Accordingly, the devices of both Odegaard and Sakasegawa et al would tend to encourage a lineman to remove his glove so that the devices thereof can be readily manipulated. This, of course, is not a desirable occurrence.
The reader may also wish to refer to the following U.S. patents in order to more fully appreciate the novel characteristics of the present invention: U.S. Pat. Nos. 3,216,684 to Larson; 2,688,655 to Gross; 3,689,686 to Wilson; 3,848,080 to Schmidt; 2,527,442 to Odegaard; and 3,491,972 to Townshend.
3. Summary of the Present Invention
As briefly alluded to above, the present invention provides a device which is easily manipulable and, moreover, provides structures which permit the clamp to function in a manner which is believed to be heretofore unknown in this art.
One of the preferred characteristics of the present invention is that it can be constructed of a rigid electrically insulating material, such as plastic so as to provide sufficient insulative properties thereto. Typically, the wire clamp of the present invention will be utilized to clamp grounding wires (e.g. bare copper wires) to a substrate. The present practice is to utilize large staples which may lead to radio and/or televison interference. Additionally, the staples tend to become loose by the staple "backing out" of the substrate or utility pole or due to the actual shrinkage of the utility pole.
These problems are alleviated according to the present invention since the plastic material is completely insulative and the securing device such as nail, spike or the like is separated from the bare copper grounding wire. Accordingly, the use of a conventional nail or spike (see Odegaard '651) will securely retain the device of the present invention and thus the bare copper grounding wire against the substrate but yet prevent any electrical interference therewith.
In accordance with the present invention, a generally U-shaped member having substantially opposing end portions is provided, the ends being initially disposed in a normal "open" position thereby defining a predetermined separation distance therebetween. A cavity to accept the wire is also defined by the U-shaped member and intermediate the cavity and the opposing ends, there is preferably provided an inclined surface, the purpose of which will become more apparent from the discussion which follows. According to the present invention, means are provided by which a person installing the device can easily and effectively manipulate the device so as to provide clamping action to the wire.
An important feature of the present invention is the provision of an upwardly inclined surface which acts as a cam of sorts so that as the device is laterally moved with respect to the wire, wedging engagement of the wire will be effected between the inclined surface and one of the legs of the generally U-shaped member. Upon continued lateral movement of the device in accordance with the present invention with respect to the wire, the wire will be relatively upwardly displaced by virtue of the incline of the surface and responsive outward displacement of the opposing ends will be effected. Continued lateral movement of the device with respect to the wire will therefore permit access to the cavity so that the wire can be accepted therein. Once the wire is accepted in the cavity, a biasing force preferably provided by the inherent properties of the material of construction of the device (e.g. a plastic material which is rigid but yet is capable of resilient deformation under sufficient force), biases the opposing ends of the generally U-shaped member into their initial separated or "open" position to frictionally engage the wire in the cavity. Such frictional engagement of the device with respect to the wire thereby prevents axial slippage of the device relative to the axis of elongation of the wire which is of great assistance to the lineman.
These and other advantages of the present invention will become more clear to the reader after careful consideration is given to the detailed description thereof which follows.